Expression for default data

I'm trying to retrieve a file that is in the following format xxxxxxx_xxxxxx.YYYYMMDDHHMISS. I can't retrieve the file with the following sql command in the parameter "Expression for default for data" as

to_char(sysdate,'YYYYMMDDHHMISS') because my command is looking for a file that is transferred at that exact time, down to the second. I could pick up the file if it was named xxxxxxx_xxxxxx.YYYYMMDD and I used the command to_char(sysdate,'YYYYMMDD'). I can't use a wait event to pick up the file, because there is no scheduler associated with this server. When I try to use the wildcard * it cancels with an error and returns the name xxxxxx_xxxxxxx.YYYYMMDD*.

Do you know a command I could use in the "Expression for default for data" that would pick up the file in the following format: xxxxxxx_xxxxxxx.YYYYMMDDHHMISS.